Much of today's important business and consumer applications rely on communications infrastructures such as the Internet. Businesses and consumers need to provide protection to their network from hostile activities while being able to communicate with others via the infrastructure. For example, businesses and consumers need to be able to send and receive voice and data packets. However, businesses and consumers also need to minimize the amount of unsolicited and undesirable content delivered to endpoint devices such as computers. The unsolicited and undesirable content is referred to as spam. For example, an undesirable and unsolicited email may be referred to as spam email. In another example, an undesirable and unsolicited voice call may be referred to as a spam voice call.
The protection of endpoint devices is typically accomplished by using a gateway or a dedicated application server to scan incoming packets and perform filtering prior to forwarding to the endpoint devices. For example, the gateway server or an email server may scan incoming emails, and redirect or remove spam emails (unsolicited and undesirable emails). Thus, the endpoint devices will not receive the spam emails.
However, some applications do not tolerate the delay associated with online scanning. For example, voice calls are typically processed in real time. For example, if a voice call is destined to a customer, then the call is forwarded towards the customer's endpoint device prior to scanning. Therefore, by the time any scanning of the content of a phone call is performed, the call has already reached the customer.